benzyl ((3aS,3bR,15aS)-2,2-dimethyl-3a,5,6,8,9,15a-hexahydro-4H-[1,3]dioxolo[4',5':4,5]cyclopenta[1,2-b][1,3]dioxolo[5',4':4,5]benzo[1,2-d]pyrrolo[1,2-a]azepin-15-yl) carbonate

2-((2R, 4R)-2-tert-butyl-4-allyl-5-oxo-1,3-dioxolan-4-yl)acetic acid